Adjustable pitch propeller



Nov. 9, 1965 s. M. CURIONI ADJUSTABLE PITCH PROPELLER 2 Sheets-Sheet 1Filed Dec. 14, 1964 Nov. 9, 1965 s. M. CURIONI 3,216,507

ADJUSTABLE PITCH PROPELLER Filed Dec. 14. 1964 2 Sheets-Sheet 2 UnitedStates Patent 3,216,507 ADJUSTABLE PITCH PROPELLER Salvatore M. Curioni,151 S. Sunset, Haysville, Kaus. Filed Dec. 14, 1964, Ser. No. 418,089 2Claims. (Cl. 170160.32)

This invention relates to propeller devices and more particularly toadjustable pitch blade propellers for use on boat outboard motors.

It has long been known that propeller blades for driving a vehiclethrough a fluid should have a low pitch for providing maximum force tothe vehicle for acceleration. At high vehicle speeds, however, the bladepitch should be increased to reduce engine r.m.p. while maintaining thevehicle speed. It is apparent, then, that the pitch of the propellerblades need be varied in relation to the vehicle motion and thereforemust be controllable through suitable mechanism while the craft is inmotion, preferably from a location remote from the engine, such as nearthe operator.

Variable pitch propellers for aircraft and certain marine vessels, whileknown in the art, have generally been complex and consequently expensivemechanisms. Such devices, therefore, are not suitable for application tooutboard engine marine vehicles because of prohibitive cost, Weight andreliabilityv Accordingly, it is an object of the present invention toprovide an adjustable pitch propeller apparatus for use on boat outboardmotors which may be used to change the blade pitch according to thevarying boat speed and load.

It is another object of the present invention to provide an adjustablepitch propeller apparatus for an outboard motor the blade position beinghydraulically controlled from a remote location.

It is still another object of the present invention to provide anadjustable pitch propeller apparatus for an outboard motor in which thecontrol arm for the blade position is biased to maintain a low bladepitch position.

For a better understanding of the invention, together with other andfurther objects thereof, reference should now be made to the followingdetailed description which is to be read in conjunction with theaccompanying drawings in which:

FIGURE 1 is an elevational View of a boat stern having an outboard motorattached thereto for use with a variable pitch propeller apparatus;

FIGURE 2 is a sectional elevation view of a variable pitch propellerapparatus;

FIGURE 3 is a plan view of the variable pitch propeller apparatus ofFIGURES 1 and 2 shown in a low-pitch position;

FIGURE 4 is a plan view of the variable pitch propeller apparatus ofFIGURES l and 2 shown in a high-pitch position;

FIGURE 5 is a sectional end view of a variable pitch propellerapparatus;

FIGURE 6 is a sectional elevation view of a portion of the variablepitch propeller apparatus shown in FIG- URE 2 in the high-pitchposition; and

FIGURE 7 is a plan view of the variable pitch propeller apparatusshowing in detail the control elements.

Referring now to FIGURE 1, there is shown a boat stern 20 to which ismounted an outboard motor 22. A housing 24 depends from the enginehousing 26 and contains a vertically disposed first drive shaft (notshown) which engages a horizontally disposed second drive shaft 28. Thelatter shaft extends into a fixed housing 30 connected to the dependinghousing 24 and is rotatable therein. As seen best in FIGURE 2, the fixedhousing 30 comprises an outer wall 32 and an inner wall 34 defining anannular space 36. A hydraulic or fluid line 40 is 3,216,507 PatentedNov. 9, 1965 connected to the outer wall 32 for pressurizing the space36 upon actuation of a hydraulic piston control device (not shown)remotely mounted from the engine such as near the boat operator. Apiston 42 having sealing rings 43 is disposed in annular space 36 andadapted to slide rearwardly, upon application of hydraulic pressure,against a thrust bearing 44. The thrust hearing has a rear or outer race46 defining a plurality of sockets 48.

Rearwardly adjacent the fixed housing 30 is a rotatable housing 50 whichis connected to shaft 28 through key 52 for rotation. A space 54 may besealed to prevent water from entering the chamber 56 by suitable meanswell known in the art. The housing 50 has an outer wall 58 and an innerwall 60 connected by members 62. A sealing plate 64 is threaded into theaft end of outer wall 58, and a hub 66 is threaded on the end of driveshaft 28 to secure the rotatable housing 50 in place. The housing 50forms a convex spherical bearing surface 68. Blades 70 are secured tohousing 50 by studs 72. The studs 72 are mounted in base 74 of theblades and are rotatably secured in the housing 50 by a snap ring 76.The under surface of base 74 is formed as a concave spherical bearingsurface for mating with the spherical bearing surface 68 formed by therotatable housing. The blades 70 rotate about the studs 72. Studs 78 aresecured in base 74 at a spaced apart location from the studs 72.

Control arms 80 each have a ball 82 which engages one of the sockets 48and are disposed in chamber 56 for slidable translation therein. Therearward end of each control arm 80 has an opening 84. The housing 50has slots 85, as seen in FIGURE 7, through which pass studs 72 whichengage the openings 84 in control arms 80.

A plurality of compression springs 86 are disposed in chamber 56, eachspring being mounted on one end over a guide pin 88.

The variable pitch propeller apparatus is set in the low-pitch position,as shown in FIGURES 2 and 3 for accelerating the boat. In this position,hydraulic pressure applied to annular space 36 displaces piston 42 andcontrol arms 80 overcoming the bias of spring 86 and thereby rotatingblades 70. When the boat reaches cruising speed, the operator mayrelieve the hydraulic pressure so that spring 86 forces piston 42forwardly and the blades 70 are rotated into a high-pitch position asshown in FIGURES 4 and 6.

While a particular embodiment of the present invention has been shownand described, it will be obvious to those skilled in the art thatchanges and modifications may be made without departing from theinvention in its broader aspects. Accordingly, the aim in the appendedclaims is to cover all such changes and modifications as fall within thetrue spirit and scope of the invention.

I claim:

1. An adjustable pitch propeller apparatus for attachment to the driveshaft of a boat motor comprising:

(a) a first fixed annular wall surrounding a drive shaft of a boatmotor,

(b) a second fixed annular wall spaced apart from said first wall andforming an annular hydraulic chamber therebetween,

(c) an annular piston slidably disposed in said hydraulic chamber,

((1) an annular thrust bearing slidably disposed in said hydraulicchamber adjacent said piston, said bearing having a plurality of socketsformed in one race,

(e) a rotatble housing surrounding said drive shaft adjacent said firstand second fixed annular walls,

(f) a plurality of radially extending adjustable pitch propeller bladesrotatably mounted on said rotatable housing,

(g) a plurality of control arms slidably disposed within 3 saidrotatable housing and between said first and second walls, one end ofeach of said control arms having a ball engaging one of said socketsformed in said thrust bearing race,

(f) a plurality of radially extending adjustable pitch (g) saidadjustable pitch propeller blade bases having concave spherical bearingundersurfaces, each of said blade bases rotatably mounted on saidrotatable housing and engaging said convex spherical bearing (h) aplurality of pins, one of said pins mounted in 5 surface formed by saidrotatable housing,

each of said blades at a spaced apart location from (h) a plurality ofcontrol arms disposed within said said rotatable mountings, each of saidpins depending rotatable housing and said fixed housing annular intosaid rotatable housing and engaging the other chamber, one end of eachof said control arms having end of each of said control arms, wherebytranslaa ball engaging one of said thrust bearing sockets, tion of saidcontrol arms rotates said propeller blades (i) a plurality of pins, eachof said pins depending so as to change the pitch of the blades, fromsaid propeller blade bases at a spaced-apart 10- (i) meansinterconnecting said rotatable housing and ation from said rotatablemounting, each of aid the drive shaft, and pins engaging the other endof one of said control (j) resilient means for biasing said annularpiston. arms, 2. An adjustable pitch propeller apparatus for attach- (j)means for interconnecting said rotatable housing ment to the drive shaftof a boat motor comprising: with the drive shaft of a boat motor, and

( a fixed housing defining an annular hydraulic (k) resilient means forbiasing said annular piston.

chamber and having a bore coaxial with said chamber and extendingthrough said housing for receiving References Cited by the Examiner adrive shaft Of a boat motor. I UNITED STATES PATENTS Qgggggglggg shdablyimposed Sald hy 1,802,808 4/31 De Narde 170l60.32 (c) an annular thrustbearing slidably disposed in said 2377457 6/45 t 170*160'37 X hydraulicchamber adjacent said piston, said bearing 3051249 8/62 Dlrhk 170 160'32having a plurality of sockets formed in one race, 3056457 10/62MwFarland 17O 160'32 X (d) a rotatable housing having a boretherethrough, 3,148,735 9/64 Mluer et 170 16O'32 coaxially aligned withthe bore of said fixed housing FOREIGN PATENTS for receiving the driveshaft, (e) said rotatable housing forming a convex spherical 116880 9/45Austraha;

bearing surface, 569,867 6/45 Great Brltaln.

SAMUEL LEVINE, Primary Examiner.

propeller blades, each of said propeller blades having JULIUS E. WEST,Examiner.

a base,

1. AN ADJUSTABLE PITCH PROPELLER APPARATUS FOR ATTACHMENT TO THE DRIVESHAFT OF A BOAT MOTOR COMPRISING: (A) A FIRST FIXED ANNULAR WALLSURROUNDING A DRIVE SHAFT OF A BOAT MOTOR, (B) A SECOND FIXED ANNULARWALL SPACED APART FROM SAID FIRST WALL AND FORMING AN ANNULAR HYDRAULICCHAMBER THEREBETWEEN, (C) AN ANNULAR PISTON SLIDABLY DISPOSED IN SAIDHYDRUALIC CHAMBER, (D) AN ANNULAR THRUST BEARING SLIDABLY DISPOSED INSAID HYDRAULIC CHAMBER ADJACENT SAID PISTON, SAID BEARING HAVING APLURALITY OF SOCKETS FORMED IN ONE RACE, (E) A ROTATABLE HOUSINGSURROUNDING SAID DRIVE SHAFT ADJACENT SAID FIRST AND SECOND FIXEDANNULAR WALLS, (F) A PLURALITY OF RADIALLY EXTENDING ADJUSTABLE PITCHPROPELLER BLADES ROTATABLY MOUNTED ON SAID ROTATABLE HOUSING, (G) APLURALITY OF CONTROL ARMS SLIDABLY DISPOSED WITHIN SAID ROTATABLEHOUSING AND BETWEEN SAID FIRST AND SECOND WALLS, ONE END OF EACH OF SAIDCONTROL ARMS HAVING A BALL ENGAGING ONE OF SAID SOCKETS FORMED IN SAIDTHRUST BEARING RACE, (H) A PLURALITY OF PINS, ONE OF SAID PINS MOUNTEDIN EACH OF SAID BLADES AT A SPACED APART LOCATION FROM SAID ROTATABLEMOUNTINGS, EACH OF SAID PIN DEPENDING INTO SAID ROTATABLE HOUSING ANDENGAGING THE OTHER END OF EACH OF SAID CONTROL ARMS, WHEREBY TRANSLATIONOF SAID CONTROL ARMS ROTATES SAID PROPELLER BLADES SO AS TO CHANGE THEPITCH OF THE BLADES, (I) MEANS INTERCONNECTING SAID ROTATABLE HOUSINGAND THE DRIVE SHAFT, AND (J) RESILIENT MEANS FOR BIASING SAID ANNULARPISTON.